Validation of candidate genes identified in the Treg transcriptome studies by real-time RT-PCR. Differentially expressed candidate genes with a significant regulation for at least 2 predefined comparisons of the Treg transcriptome studies (Table 4) have been analyzed by real-time RT-PCR in an independent larger group of patients. Patients without GVHD and with GVHD manifestation before day 100 and after day 100 after SCT are summarized as “no GVHD” or “GVHD” < 100 days and > 100 days, respectively. Isolated RNAs from sorted CD4⁺CD25^hiCD127^lo/− T cells were transcribed, and cDNAs were pooled from n = 12 patients without GVHD in 4 cDNA pools, n = 27 patients with GVHD in 9 cDNA pools, and n = 9 healthy donors (HD) in 3 cDNA pools. The results of real-time RT-PCRs are presented as mean values of relative mRNA expression levels to the housekeeping genes RPS9 and GAPDH, respectively. *P < .05 (significant, 2-paired Student t test). ***P < .001 (highly significant, 2-paired Student t test).